Camp Mabry's original 85-acre (34 ha) site, overlooking the Colorado River three miles (5 km) northwest of downtown Austin, was donated by the city to the state in 1892.

It was initially a literal "camp", a space in which the Texas Volunteer Guard encamped during the summers while hosting mock battles and demonstrations for the people of Austin.

In 1909 the camp was greatly enlarged by the addition of 200 acres (81 ha) of land purchased by the federal government for use in training the state national guard.

In 1915 an arsenal became the first permanent structure built onsite, allowing military equipment and weapons to be moved out of storage in the capitol building.

Prior to the September 11th attacks, Camp Mabry's mile-long track that sits adjacent to Mopac was a popular destination for walkers and joggers, and the field within it was used by many youth sports teams.